458win: I have a 35 caliber X bullet recovered from an elk that failed to open up as well. I thought they had these ironed out by now.

I have killed 4 elk, 1 kudu, 6 deer (whitetails and mule deer) one hog, 3 antelope, 1 steinbok, 1 springbok, 1 mountain reedbok, 1 impala - all with a .280 using Nosler Partition. I have no complaints and will keep on using them.

My sons took several African animals with .243 and .270 using Nosler Partitions. No problems when hit properly.

My only problem was hitting an impala in the back leg - then needing a finishing shot.